#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

const int NLIM = 100005;
int N,M;
int insule=0;
bool vizitat[NLIM];
vector < int > Muchii[NLIM];

void DFS(int Nod)
{
    vizitat[Nod] = true;
    for(unsigned int i = 0; i < Muchii[Nod].size(); i++)
    {
        int Vecin = Muchii[Nod][i];
        if(!vizitat[Vecin])
            DFS(Vecin);
    }
}

void Citire()
{
    f >> N >> M;
    for(int i = 1; i <= M; i++)
    {
        int x,y;
        f >> x >> y;
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);
    }
    for (int i = 1; i <=N; i++)
    {
        if(!vizitat[i]){
            insule+=1;
            DFS(i);
        }
    }
}

int main()
{
    Citire();
    g  << insule << "\n";
    return 0;
}